By its name, this 128-Bin Resistor Kits use our patented Super Enclosure which has 128 individually lidded and labeled bins for storing up to 128 different types of SMD resistors.  The kits are categorized by the size of the resistors, the number of values/kit, and the number of pieces/value. Please note that for the 170 value kit, it covers approximately the E-24 series resistance values, implemented by 5% resistors.